A new entrepreneurial approach to that perfect cup of coffee in the morning: Coffee Joulies.That largish, metallic "coffee bean" is not just a paper weight to say how much you love coffee. Supposedly it's filled with a phase-changing substance that will both quickly cool your coffee to an ideal temperature and then keep it from cooling quite as fast after that. Though I find the reference to it being filled with a phase-changing material a little non-specific and bordering on marketing woo. I mean, water is a phase changing substance.